For once, a 100% reproducible crash! Sadly, the backtrace isn't great and I have no idea what to do with it. But reproducible is nice. This occurs in Tech Preview wiht 2.25.4. (gdb) bt full #0 0x00007f29cdd364f8 in WTF::Vector<Nicosia::CairoOperationRecorder::State, 32ul, WTF::CrashOnOverflow, 16ul>::expandCapacity(unsigned long) (this=0x55dc2b6f4cf0, newMinCapacity=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/Vector.h:286 #1 0xcf0a1a0f11977054 in () #2 0xcea349636cd37054 in () #3 0x00007f2900000000 in () #4 0x00007f29c9ade573 in JSC::Heap::collectAsync(JSC::GCRequest) (request=..., this=0x7f29bf642e10) at ../Source/JavaScriptCore/heap/Heap.cpp:1123 previousRequest = <optimized out> __for_range = @0x7f29bf643270: {m_start = 0, m_end = 0, m_buffer = {<WTF::VectorBufferBase<JSC::GCRequest>> = {m_buffer = 0x0, m_capacity = 0, m_size = 0}, <No data fields>}} locker = {<WTF::AbstractLocker> = {<No data fields>}, m_lockable = 0x7f29cb7b0cf0 <_int_malloc+2112>} alreadyRequested = false #5 0x00007f29c9ade573 in JSC::Heap::collectAsync(JSC::GCRequest) (this=0x7f29bf642e10, request=...) at ../Source/JavaScriptCore/heap/Heap.cpp:1112 #6 0x0000000000000000 in () To reproduce; * Visit https://www.ksdk.com/article/news/local/galleria-shots-fired/63-c17a629f-85b3-4348-b8a5-8a3f52e6deaa * Scroll down to the Google Maps widget * Click on "View larger map" * A new related view will be created. The web process backing both the original view and the related view crash.